植體輔助式局部活動牙科贋復物是修復部分缺牙的一種治療選擇，而植體的植入位置會影響義齒之生物力學表現。本研究以遠心游離端部分缺牙情況，建立病患三維有限元素模型，並分析不同鄰近支柱牙冠根比、鉤靠放置位置及不同缺牙顆數對應力分佈的影響。
其中IARPD具有鄰近支柱牙鉤靠及對側牙鉤，而植體（5×11.5mm）垂直於咬合平面分別植入於各缺牙牙位，並施加200 N垂直力到IARPD的第二大臼齒上，並比較顎骨以及牙齦上等效應力的峰值。
植體植入於遠心端時支柱牙周圍皮質骨的最大等效應力較近心端降低75.9%，而牙齦上的接觸壓力則下降了89.6%，然而植體周圍皮質骨的最大等效應力卻上升了66.8%。近心鉤靠造成支柱牙周圍皮質骨的最大等效應力較遠心鉤靠上升25.4%，而支柱牙冠根比為1.5:1時於支柱牙周圍皮質骨的最大等效應力較冠根比為1:1時上升33.9%。
IARPD採用遠心鉤靠搭配遠心端植體能降低患者不適，當冠根比上升時應避免使用近心鉤靠，以避免支柱牙周圍骨的損傷。

This study investigated the biomechanical influence of the implant position on the dental prosthesis with distal extension and stress distribution. The mandibular implant-assisted removable partial denture (IARPD) with distal extension was analyzed. The stress distribution of IARPDs was evaluated under different crown- root ratios of the abutment tooth, types of occlusal rest, and numbers of missing teeth. When the implant was placed at the distal side, the maximum von Mises stress of the cortical bone around the abutment tooth was 75.9% lower than that of the mesial side. Simultaneously the maximum von Mises stress on the mucosa decreased by 89.6%, while the maximum von Mises stress of the cortical bone around the implant increased by 66.8%. The distally inserted implant can effectively reduce the stress on the abutment tooth and the discomfort of the mucosa. IARPDs with a distal occlusal rest direct retainer can reduce the risk of failure of the abutment tooth. When the crown-root ratio of the patient’s abutment tooth was relatively high, inserting the implant in the middle position should be avoided. This study performed a complete biomechanical analysis of IARPDs as well as the consequent discomfort and complications, which could provide new insights for planning the procedure.

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